Why can computer software be protected by both copyright law and patent law?

Computer software can be protected by both copyright and patent law because these fields of intellectual-property law have increasingly overlapped, allowing developers to utilize multiple legal frameworks to secure their inventions.1

Historically, these areas of law were considered distinct. However, during the latter half of the 20th century, the boundaries between them blurred as their practical applications began to intersect. Specifically:1

• Copyright Law: In the 1970s, copyright protections were extended to include computer software, protecting the expression of the code itself.1
• Patent Law: During the 1980s and 1990s, courts in many jurisdictions ruled that software could also be protected through patent law, which covers the functional aspects or processes of the invention.1

By relying on both fields, developers can more effectively prevent rivals from selling identical or closely similar programs and stop consumers from making unauthorized copies. This dual protection is part of a broader trend where intellectual-property rights are increasingly consolidated to provide robust safeguards for technological and creative works.1